Shipboard magazine sprinkler systems employ hydraulically actuated control valves that are required to open rapidly, in less than one second, in the event of a fire in the magazine. Such control valves, which may be eight inches or more in diameter, employ high capacity three-way power operated valves for their actuation. Preferably the actuating valves are direct acting, since pilot operated valves add unnecessary complexity and are too slow. Thus a direct acting valve is required for actuation of the large hydraulically controlled sprinkler control valve. The valve must have a high capacity for rapid actuation of the sprinkler control valve. It must be capable of sealing against high sea water pressures, in the order of 250 pounds per square inch, without leaking, and yet it must be capable of remote power operation by power units of reasonable size. For example, for a conventional three quarter inch diameter valve to be able to open against 250 pounds per square inches of pressure, an opening force of approximately 110 pounds is required. Such a large force is not available from a conveniently sized solenoid without an unacceptably large current flow.
The conventional spool valve in which flow passes about decreased diameter portions of the spool has a relatively limited capacity for its size because of the flow restriction imposed by the spool itself. Further, such spool valves require a relatively large number of sliding seals, which seals are subject to being pinched, abraded and torn as the spool and seals move into and out of valve ports or relieved areas of the spool. Thus it would be desirable for improved valve operation to increase the flow capacity, to decrease the number of O-rings or seals, and to provide a configuration that increases the life of the seals.
Applicant is unaware of any presently existing valve that would meet such requirements.
Accordingly, it is an object of the present invention to provide a valve that eliminates or minimizes disadvantages of prior valves and provides a rapid high capacity flow in a substantially balanced arrangement. Although the embodiments of the valve disclosed herein are specifically designed for actuation of magazine sprinkler control valves, principles of the present invention may be employed in many different types of valves, whether or not bistable or three-way, and in many different configurations and applications as will become apparent to those skilled in the art.